As semiconductor trends continue toward decreased size and increased packaging density, every aspect of semiconductor fabrication processes is scrutinized in an attempt to maximize efficiency in semiconductor fabrication and throughput. Many factors contribute to fabrication of a semiconductor. For example, at least one photolithographic process can be used during fabrication of a semiconductor. This particular factor in the fabrication process is highly scrutinized by the semiconductor industry in order to improve packaging density and precision in semiconductor structure.
Lithography is a process in semiconductor fabrication that generally relates to transfer of patterns between media. More specifically, lithography refers to a transfer of patterns onto a thin film that has been deposited onto a substrate. The transferred patterns then act as a blueprint for desired circuit components. Typically, various patterns are transferred to a photoresist (e.g., radiation-sensitive film), which overlies the thin film on the substrate during an imaging process described as “exposure” of the photoresist layer. During exposure, the photoresist is subjected to an illumination source (e.g., UV-light, electron beam, X-ray), which passes through a pattern template, or reticle, to print the desired pattern in the photoresist. Upon exposure to the illumination source, radiation-sensitive qualities of the photoresist permits a chemical transformation in exposed areas of the photoresist, which in turn alters the solubility of the photoresist in exposed areas relative to that of unexposed areas. When a particular solvent developer is applied, exposed areas of the photoresist are dissolved and removed, resulting in a three-dimensional pattern in the photoresist layer. This pattern is at least a portion of the semiconductor device that contributes to final function and structure of the device, or wafer.
Furthermore, throughput considerations and design rules have resulted in an industry-wide desire for systems and/or methodologies that facilitate reducing costs and increasing output without sacrificing quality. Thus, a need exists in the art for systems and/or methodologies that overcome the afore-mentioned deficiencies.